Statue of Liberty, New York City
When Ainissa Ramirez was growing up in Jersey City, she needed only to look east to see the Statue of Liberty on the horizon. Scaling the 354 stairs to the crown with her family or on class trips, she was always thrilled by the sheer magnitude of the monument. Now a materials scientist and a science education reformer at Yale University, Ramirez appreciates Lady Liberty as much more than an iconic tourist destination. She sees it as the ultimate metallurgical success story, a structure whose combination of materials has allowed it to withstand more than 125 years of the harshest of environments: hot summers, cold winters, and the salt spray of the surrounding sea.
The 156-ton monument stands on Liberty Island, just a 20-minute ferry ride from Manhattan or New Jersey. Unveiled in 1886, the statue was famously a gift from France to America, celebrating 100 years of independence and the Union victory in the Civil War. Its message of freedom for all citizens, particularly former slaves—reinforced by broken shackles that lie at Lady Liberty’s feet—resonated with Ramirez long before she understood the science behind its construction.
Inside the statue, it is easy to spot how thin the outwardly imposing structure actually is. “You can see the wavy contour of the robe,” Ramirez says, “and if you knock on it, you can hear a sound that tells you it’s not very thick,” much like hitting a chimeless bell. The statue’s copper skin is less than one-tenth of an inch thick, about the same as two pennies pressed together. Auguste Bartholdi, the French sculptor who designed the structure, knew the metal would expand with heat, so he affixed the thin copper sheets to the frame with buckle-shaped copper braces. This gives each piece of copper some freedom to move, while the iron skeleton—designed by engineer Gustave Eiffel, who used the statue’s wrought-iron frame as a proof of concept for his eponymous tower—provides structural support. The braces are clearly visible inside the statue, along a seam that runs down the center of Lady Liberty’s face.
Visitors were allowed to the top of the torch until 1916, when an explosion set off by German agents sabotaging a nearby munitions dump damaged the raised arm. More recently, members of the public have been permitted as high as the head. (The statue is closed for renovations through late this year; until then, visitors can still tour Liberty Island for an up-close view.)
Flexibility isn’t the only reason copper has proved a sound materials choice for the statue, Ramirez says. Bartholdi selected it over heavier bronze to reduce the weight of materials shipped across the Atlantic. And while salt in the air can accelerate corrosion, Ramirez says, it also adds to a protective covering on the statue called a patina, the result of oxygen, carbon dioxide, and other compounds reacting with the copper. That layer formed over Lady Liberty’s first 30 years, giving her copper-colored skin its current greenish hue.
The patina hasn’t protected the statue from more than a century’s exposure to the elements on its own. Engineers have not only patched holes and plugged leaks but made significant structural upgrades as well. Saltwater hitting the statue’s iron skeleton and copper skin set up a galvanic cell, Ramirez says, an electrochemical reaction that caused the copper to corrode. Many iron components have been swapped out for stainless steel.
The statue’s persistence is, to Ramirez, something of a monument in itself. “It’s kind of amazing to me that it’s still standing,” she says. “Here you have this metal in the most corrosive environment possible—seawater—and it’s still there.”
THE TOUR GUIDE
Ainissa Ramirez, a Yale University materials scientist, invented the universal solder, an alloy now used in semiconductors that can attach metals to glass, ceramics, and diamonds.
NEIGHBORING SCIENCE SIGHTSEEING
The area around New York Harbor is crammed with touristy activities and world-famous sights, but it is also home to lesser-known destinations that will appeal to scientifically curious visitors.
The Liberty Science Center in Jersey City has interactive exhibits on alternative energy, skyscrapers, and infectious microbes. It also has the world’s largest Hoberman sphere, an 18-foot-wide collapsible metal polyhedron that contracts and expands at regular intervals. lsc.org
The Museum of American Finance in Manhattan offers visitors a peek at the inner workings
and occasional malfunctionsof capitalism, with exhibits that explore and explain the intricacies of financial markets, the history of money, and the recent credit crisis. moaf.org
A Tour of New York’s Harbor Heron Islands offers a sunset glimpse of the coastal birds during their summer breeding season, and egrets, cormorants, and other wildlife year-round. A 90-minute boat ride also provides views of the Manhattan skyline. viator.com
OCTOBER 4 World Space Week
Celebrate the launch of Sputnik and the dawn of the space age at hundreds of events here and abroad.
OCTOBER 5 Frankenweenie
Tim Burton updates Mary Shelley’s
classic to tell the story of a 10-year-old boy genius who brings his beloved dog back to life.
OCTOBER 8-10 Nobel Prizes
The Oscars for geeks: Announcements of the Nobel winners in Medicine, Physics, and Chemistry.
OCTOBER 10 World Mental Health Day
For 2012, the World
Health Organization is
promoting public awareness of depression, which affects 121 million people across the globe.
OCTOBER 18 Sun Kissed, PBS
The true story of a couple who learn they carry a rare gene that can make exposure to sunlight fatal.
ON GOING National Cyber
Security Awareness Month
With great connection
speed comes great responsibility. Learn what you can do to help safeguard your life online.
OCTOBER 13-17 Neuroscience 2012
30,000 brain experts descend on New Orleans
to cogitate on everything from the ethics of smart drugs to language
exposure in the womb.
OCTOBER 14 OCEANS ’12 Conference, Virginia Beach
Everything you could want
to know about “harnessing the power of the ocean.”
OCTOBER 14-20 Earth Science Week
Tap into your inner geoscientist by planting a garden that measures the ozone layer or by testing the quality of your soil.
OCTOBER 18 National Science Teachers Association
Oct. 18. Educators meet in Louisville to craft teaching tools for “Science—
OCTOBER 20 National Archaeology Day
Your turn to dig into history.
OCTOBER 21 Orionids
Wake early to see one of the year’s best meteor showers at its peak.